"Moose the Mooche" is a bebop composition written by Charlie Parker in 1946. It was written shortly after his friend and longtime musical companion Dizzy Gillespie left him in Los Angeles to return to New York City. Charlie Parker had been a long time heroin addict and had been using since he was 17. Some historians suggest that the song was named after the drug dealer that sold him drugs for several years before being arrested.
This composition is in the key of B-flat and has a 32-bar AABA structure. The chord progression is based on the I Got Rhythm changes and makes extensive use of the ii-V-I turnaround. Typical of many bebop compositions, 'Moose the Mooche' is played at a fast tempo (Quarter Note = 224).
Over the years the song has gained considerable fame and has become a bebop standard. Among the artists that have covered it are Dizzy Gillespie, Jay Thomas, Bud Powell, Phish, Sadao Watanabe, Joshua Redman, and Stevie Wonder.